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by Robert Sanders, Public Affairs An extract of pine bark has proven to be one of the most potent antioxidants, a property that may explain why pine bark has been used in folk medicine around the world, according to a new report by Berkeley scientists. Lester Packer and his colleagues screened many natural compounds for antioxidant activity and found that pine bark extract, marketed as Pycnogenol® (pik-nah-je-nal), is the most potent of the lot. Antioxidants are chemicals that deactivate free radicals – highly destructive chemicals that damage cells and contribute to many diseases, ranging from stroke and heart attacks to degenerative diseases such as Alzheimer’s. Free radicals even contribute to aging. In the past year and a half, Packer and his colleagues have documented a number of strong antioxidant effects of Pycnogenol that place it among the most potent antioxidants, ranking with vitamins E and C, and lipoic acid. Packer, a professor of molecular and cell biology, also recently found that Pycnogenol extends the lifetime of vitamin C in the body, prolonging its beneficial effects as an antioxidant. These beneficial effects of Pycnogenol come atop immune system benefits reported last year by Packer and his group. They found that Pycnogenol suppresses the production of nitric oxide (NO) and thus limits the collateral damage resulting from immune system attacks on viral and bacterial invaders. Excess NO has been linked to inflammation, rheumatoid arthritis and Alzheimer’s disease. “It’s not too early to say that Pycnogenol is a good supplement to take along with vitamins C and E, and lipoic acid,” Packer says. He reported his results Feb. 6 at the annual meeting of the Oxygen Club of California, an international meeting that this year drew nearly 300 scientists from around the world who study the beneficial effects of antioxidants. The ’98 World Congress was held in Santa Barbara Feb. 5 to 8. Pycnogenol is a combination of some 40 chemicals extracted from the bark of the French maritime pine, Pinus pinaster, which grows in many areas along the Atlantic coast of France and into North Africa. Extracts and teas of pine were commonly used by early Europeans and native Americans, and reportedly are used in Asian medicine as well. While many scientists eschew research on chemical mixtures like Pycnogenol, Packer has long seen the value of looking at natural plant extracts, most of which are a mélange of chemicals. For the past five years, for example, he has been studying the effects of an extract of the tree Gingko biloba, called EGb761, and has found important antioxidant effects there as well. “Recently an extract of Gingko biloba was found to have beneficial effects on those with Alzheimer’s disease and dementia,” Packer says, referring to an October 1997 article in the Journal of the American Medical Association on the effects of EGb761. “What we have been doing with these extracts was the basis for these studies.” Because his initial studies showed that Pycnogenol is one of the most potent antioxidants, he decided to look in detail at the cellular effects of the extract. Pycnogenol earlier had been shown to have a beneficial effect on the circulation, primarily through its effects on nitric oxide, a chemical that stimulates dilation of the blood vessels. In this case Pycnogenol was found to constrict the blood vessels and increase blood flow. NO also plays other roles in the body, from destroying bacterial invaders and cancer cells to relaying signals in the brain. In the past one and a half years, he and post-doctoral colleagues Fabio Virgili, Hirotsugu Kobuchi and Elaine Cossins have documented the details of Pycnogenol’s interaction with NO. Last year they showed that Pycnogenol affects the production of NO in the white blood cells called macrophages – scavenger cells that spew out NO to destroy invading bacteria, viruses and cancer cells. While NO production is essential for a well-functioning immune system, too much in the wrong tissues can cause damage. Packer and his group showed that Pycnogenol can inhibit the body’s key NO-activating enzyme and also the gene for that enzyme. In addition, Pycnogenol quenches NO directly. In their new report, the same researchers find that Pycnogenol also extends the lifetime of vitamin C, based on test tube experiments. “We looked at extracts of fruits and vegetables, gingko, green tea and many other plants, as well as purified flavonoids, and among these Pycnogenol was the most potent in extending the lifetime of the vitamin C radical,” Packer says. “There may be many flavonoids in Pycnogenol that affect the antioxidant network by interacting at the level of vitamin C. This helps to explain how pine bark extract has a beneficial effect.” Flavonoids or polyphenols are plant compounds used widely in traditional medicine, and in more recent times have been shown to be antioxidants. Many have been found to counteract inflammation or to have beneficial effects on circulation. Packer has proposed a complex network of interactions between vitamin E, vitamin C (ascorbate) and other chemicals that effectively recycle these potent antioxidants and extend their effect in the body. Flavonoids like those in Pycnogenol seem to insinuate themselves into the network to help recycle E and C and extend their lifetimes even more. He hopes that more research will reveal further health implications of these findings. Packer’s work is supported in part by unrestricted gift funds
to the University of California and by Horphag Research, Ltd.
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